Method for parachute reefing control

ABSTRACT

A method for controlling the drag area growth of a parachute canopy during airborne descent with sensors attached to the payload for facilitating modification of the schedule of release of a parachute canopy reefing mechanism. A control processor is included that can receive and/or calculate a schedule for disengaging the reefing on the parachute. One or more wireless transmitters at the payload transmit the releasing signal from the payload to the reefing mechanism normally located adjacent the parachute canopy. The control processor can also be configured to receive input information from multiple sensors attached to the payload that monitor parameters such as altitude, position, load force, dynamic pressure, time and others to facilitate instantaneous recalculation of the disreefing schedule responsive to such conditions.

This application is a division of and claims filing priority of U.S.patent application Ser. No. 11/414,677 filed Apr. 28, 2006 by the sameinventors as set forth herewithin, currently pending and assigned toPioneer Aerospace Corporation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention deals with the field of airborne descent controldevices such as parachutes and other gliding wing constructions whichare attached to payloads therebeneath such as capsules used for returnof individuals or equipment from space travel. Such parachute devicesnormally need to be reefed in order to restrict or at least control theinflation of the canopy thereof in order to assure a gradual properlyformed movement of the canopy from the fully collapsed position withinthe parachute pack prior to deployment to the fully inflated position.Often multiple stages of such reefing are utilized in order to assurethat the canopy gradually moves from the closed position to the fullyinflated position to avoid excessive loads or the exposure thereof toimproper inflation forces which might damage or otherwise inhibit thefull canopy inflation.

Most parachute reefing is accomplished with a continuous line that isinstalled in the parachute skirt or mouth or lower surface and then iscut at a discrete time which is predetermined on the basis of loadlimitations and other aerodynamic considerations. Often mechanicallyactuated pyrotechnic reefing cutters are used for cutting this line.Normally these cutters are present with a specific time delay and cannotbe adjusted for different conditions after installation or packing.

It should be appreciated that parachute reefing can occur in severalmultiple stages from one or two stages to as many as five stages ormore. Reefing is used primarily for controlling the forces of canopyinflation. If a reefing line fails or if a reefing cutter operatesprematurely, the canopy inflation can exceed design force levels. If areefing line is not completely severed or if a cutter fails to operate,the canopy will not reach full inflation and excessive descent ratesand/or ground impacts can result. Redundant cutters and cutteractivation signals herein are intended to provide back-up operation tothis critical function. Also included within the present invention is aninhibiting feature to prevent disreefing beyond certain conditions.

2. Description of the Prior Art

Some parachutes which are used for controlling airborne descent ofpayloads include electrically actuated pyrotechnic reefing cutters whichallow an electrical signal to provide flexibility and optimumperformance. However, because the reefing cutters must be installed onthe parachute skirt for proper inflation control, these electricalcables can become excessively heavy and risky to the reliability ofoperation of the parachute due to the length and necessary slack of thefairly heavy electrical cable. The present invention provides a uniquemeans for controlling the disengagement of the reefing in one ormultiple stages of such a parachute canopy. Parameters monitored bysensors on the payload are used to trigger the reefing disengagementmechanism located at the parachute skirt without requiring any suchelectrical cables. Some patents have been granted on remotely positionedcontrol devices for parachutes all of which are significantly differentfrom the present invention such as U.S. Pat. No. 2,427,979 patented Sep.23, 1947 to A. J. Sorensen and assigned to The Union Switch & SignalCompany on a “Communication And Control System For Airplanes”; and U.S.Pat. No. 2,490,844 patented Dec. 13, 1949 to E. M. Sorensen on a “RadioRemote-Control Aircraft System”; and U.S. Pat. No. 2,925,234 patentedFeb. 16, 1960 to F. A. Wodal et at and assigned to Earle W. Wallick andTemple N. Joyce on an “Aircraft Remote Proportional Control Mechanism”;and U.S. Pat. No. 2,966,316 patented Dec. 27, 1960 to N. E. Ward et aland assigned to the United States of America as represented by theSecretary of the Navy on a “Missile”; and U.S. Pat. No. 3,146,976patented Sep. 1, 1964 to M. J. Houdou on a “Parachute”; and U.S. Pat.No. 3,193,223 patented Jul. 6, 1965 to S. Davis on a “Parachute ReleaseControl”; and U.S. Pat. No. 3,204,368 patented Sep. 7, 1965 to W. L.Effinger, Jr. et al and assigned to The A.C. Gilbert Company on a“Self-Powered Model Paraglider”; and U.S. Pat. No. 3,443,779 patentedMay 13, 1969 to F. M. Rogallo et al and assigned to the United States ofAmerica as represented by the Administrator of National Aeronautics andSpace Administration; on “Aeroflexible Structures”; and U.S. Pat. No.3,920,201 patented Nov. 18, 1975 to W. R. Battles on a “Pilotless GliderConstruction”; and U.S. Pat. No. 4,175,722 patented Nov. 27, 1979 to M.W. Higgins on a “Control System For Ram Air Gliding Parachute”; and U.S.Pat. No. 4,180,221 patented Dec. 25, 1979 to D. E. Harris on a “SelfPropelled Kite”; and U.S. Pat. No. 4,440,366 patented Apr. 3, 1984 to A.A. Keeler et al and assigned to Commonwealth of Australia on a“Parachute Control Apparatus”; and U.S. Pat. No. 4,601,443 patented Jul.22, 1986 to A. W. Jones on a “Free Flyable Structure”; and U.S. Pat. No.4,865,274 patented Sep. 12, 1989 to J. A. Fisher and assigned to UnitedTechnologies Corporation on a “Passive Control Assembly For GlidingDevice”; and U.S. Pat. No. 4,934,630 patented Jun. 19, 1990 to S. L.Snyder on a “Powered Airfoil Canopy Aircraft”; and U.S. Pat. No.4,948,071 patented to C. M. Summers on Aug. 14, 1990 on a “DeploymentSystem For Parachute”; and U.S. Pat. No. 4,955,563 patented Sep. 11,1990 to C. K. Lee et al and assigned to the United States of America asrepresented by the Secretary of the Army on an “Apparatus And Method ForControlled Simultaneous Opening Of Clustered Parachutes”; and U.S. Pat.No. 5,080,305 patented Jan. 14, 1992 to F. B. Stencel on a “Low-AltitudeRetro-Rocket Load Landing System With Wind Drift Counteraction”; andU.S. Pat. No. 5,160,100 patented to S.s L. Synder on Nov. 3, 1992 on an“Airfoil Canopy Aircraft”; and U.S. Pat. No. 5,620,153 patented Apr. 15,1997 to H. M. Ginsberg on a “Light Aircraft With Inflatable ParachuteWing Propelled By A Ducted Propeller”; and U.S. Pat. No. 5,678,788patented Oct. 21, 1997 to W. Hetzer et al and assigned to Daimler-BenzAerospace AG on a “Steering Device For A Glider”; and U.S. Pat. No.6,042,056 patented Mar. 28, 2000 to J. P Chopard and assigned toDelegation Generale pour I'Armement on an “Air Carrier Steerage ControlDevice”; and U.S. Pat. No. 6,293,202 patented Sep. 25, 2001 to R.Woodall et al and assigned to The United States of America asrepresented by the Secretary of the Navy on a “Precision, AirborneDeployed, GPS Guided Standoff Torpedo”; and U.S. Pat. No. 6,322,021patented Nov. 27, 2001 to J. A. Fisher et al and assigned to AdvancedSystems Technology, Inc. on a “Deployable Wing With Propulsion For RangeExtension”; and U.S. Pat. No. 6,343,244 patented Jan. 29, 2002 to H.Yoneda et al and assigned to Fuji Jukogyo Kabushiki Kaisha on an“Automatic Guidance System For Flight Vehicle Having Parafoil AndNavigation Guidance Apparatus For The System”; and U.S. Pat. No.6,364,251 patented Apr. 2, 2002 to J. H. Him on an “Airwing Structure”;and U.S. Pat. No. 6,416,019 patented Jul. 9, 2002 to D. P. Hilliard etal and assigned to The United States of America as represented by theSecretary of the Navy on a “Precision Parachute Recovery System”; andU.S. Pat. No. 6,503,119 patented to B. K. Lapointe on Jan. 7, 2003 on a“Parachute Toy”; and U.S. Pat. No. 6,505,793 patented Jan. 14, 2003 toH. J. Schwarzler and assigned to EADS Deutschland GmbH on an “ActuationSystem And Method For A Load-Bearing Paraglider”; and U.S. Pat. No.6,587,762 patented Jul. 1, 2003 to H. B. Rooney and assigned to FXCCorporation on an “Automatic Guidance Unit For Aerial Delivery Unit”;and U.S. Pat. No. 6,6,622,968 patented Sep. 23, 2003 to D. S. Clair etal and assigned to Edward Strong on a “Guided Airborne Vehicle, CargoAnd Personnel Delivery System”; and U.S. Pat. No. 6,676,084 patentedJan. 13, 2004 to J. Asseline et al and assigned to Institut de Recherchepour le Developpement on a “Small-Sized Radio-Controlled Flying Device”;and U.S. Pat. No. 6,830,222 patented to K. T. Nock et al on Dec. 14,2004 and assigned to Global Aerospace Corporation on a “Balloon DeviceFor Lowering Space Object Orbits”; and U.S. Pat. No. 6,845,948 patentedJan. 25, 2005 to P. J. Thomas and assigned to Paul J. Thomas on an“Adaptable Kite/Airfoil”; and U.S. Pat. No. 6,877,690 patented Apr. 12,2005 to A. J. Bragg on a “Combination Powered Parachute And Motorcycle”;and U.S. Pat. No. 6,889,942 patented May 10, 2005 to D. Preston andassigned to Atair Aerospace, Inc. on a “Steerable Parachute ControlSystem And Method”; and U.S. Pat. No. 6,923,404 patented Aug. 2, 2005 toD. D. Liu et al and assigned to ZONA Technology, Inc. on an “ApparatusAnd Methods For Variable Sweep Body Conformal Wring With Application ToProjectiles, Missiles, And Unmanned Air Vehicles”; and United StatesPatent Publication No. US 2003/0164426 A1 to D. St. Clair et al on a“Guided Airborne Vehicle, Cargo And Personnel Delivery System”.

SUMMARY OF THE INVENTION

The present invention provides a unique method and apparatus forparachute reefing control which is usable with a payload attached solelythrough suspension lines to a parachute having a canopy and a multiplystaged canopy reefing device and a reefing release mechanism forcontrolling canopy inflation and airborne descent after deployment. Theparachute reefing control apparatus may include a plurality of sensorsmounted with respect to the payload for monitoring parameters tofacilitate determination of a release schedule for disengaging thereefing of the parachute canopy. The sensing mechanism can include amission time clock which monitors the time elapsed since deployment ofthe parachute and the payload. The sensing devices can also include aglobal positioning system device for the purpose of instantaneouslymonitoring the position of the payload relative to the earth therebelowand to facilitate more precision in determining the location of landingof the parachute. With ongoing GPS monitoring, it is possible to disreefthe parachute at the optimal altitude to account for wind drift and, inthis manner, minimize the distance from a landing target. Furthermorethe sensor array can include a pressure sensing mechanism for monitoringthe dynamic pressure being exerted instantaneously on the payload. Alsoa load sensing means can be included in the sensing array for thepurpose of sensing the load force of the canopy. Other conditions can bemonitored for the purpose of providing information for determiningcontinuously and instantaneously on an ongoing basis what the releaseprofile or release schedule should be for the disengagement of thereefing mechanism for the canopy of the parachute.

A reefing control processor is also included which is mounted withrespect to the payload and is operatively connected to the sensing meansfor receiving information on all the parameters sensed by the sensingarray in order to utilize this to calculate a release schedule. Thisrelease schedule will generate one or more release signals which areoperable to initiate disengagement of all or part of the reefingmechanism. A wireless transmitter means is also included mounted withrespect to the payload and operatively connected to the reefing controlprocessor. This wireless transmitter is responsive to receiving releasesignals from the reefing control means to transmit a wireless signaltherefrom.

Further included in the present invention is a wireless receiver meansattached with respect to the parachute canopy which is operative to beactuated responsive to sensing the generation of a wireless signal bythe wireless transmitter to initiate operation of the reefing releasemechanism. Normally this reefing release mechanism can include more thanone individual stage and, as such, the wireless receiver will beresponsive to receiving the individual wireless signals from thewireless transmitter to disengage each canopy reefing stagesequentially. When utilizing more than one stage the initial stage willallow partial inflation of the canopy by partial disreefing thereof andcomplete reefing will follow in the second or subsequent stages untilfull disengagement of the reefing mechanism is achieved which will thenallow full inflation of the canopy.

The apparatus of the present invention can also include a parachutedeployment inhibiting mechanism which is attached to the payload and isoperatively positioned between the reefing control processor and thewireless transmitter to prevent deployment of the parachute unless allparameters being monitored by the sensing means are within predefinedtolerance value limitations.

The apparatus of the present invention can also include a first signaland an additional signal wherein the second signal is a redundant backupsignal to insure that full disreefing has occurred. The canopy releasedevice preferably includes at least one line extending around the canopysuch as to restrict parachute canopy inflation. Furthermore the reefingrelease mechanism further includes at least one electrically-firedcutter positioned adjacent to the line for cutting thereof responsive toactuation of the reefing release mechanism.

It should be further appreciated that the method of the presentinvention can be practiced in such a manner as to not require any directconnection between the payload and the parachute other than throughsolely the conventional suspension lines extending from the canopy tothe payload. This is achieved by monitoring a plurality of parameterswith a sensor array which is mounted on the payload. Thereafter areefing control processor is provided mounted on the payload whichcontinuously receives information on the monitored parameters from thesensor for instantaneously determining a release schedule for thereefing of the parachute canopy. Thereafter at least one wireless signalis transmitted from the payload to the reefing release mechanism mountedadjacent the reefing device at the parachute canopy. This signal isreceived at the canopy to facilitate actuation of a reefing releasemechanism positioned adjacent to the canopy and preferably adjacent tothe skirt of the canopy to allow at least partial inflation of theparachute canopy to facilitate control descent thereof with the payloadattached thereto. If additional stages of reefing need to be disengagedthen additional wireless signals can be generated by the reefing controlprocessor and transmitted to the wireless receiver attached adjacent tothe reefing release mechanism. In this manner once the final reefing isdisengaged the canopy will be capable of full inflation to efficientlyand effectively control airborne descent of the payload.

It is an object of the method for parachute reefing control of thepresent invention to provide a smart reefing system responsive tocontinuously monitor parameters for fast and yet efficient fullinflation of a parachute canopy.

It is an object of the method for parachute reefing control of thepresent invention to provide a system which can quickly respond to realtime changes in mission profile such as aborted missions and high windsand other unusual circumstances.

It is an object of the method for parachute reefing control of thepresent invention to provide the use of wireless technology including awireless transmitter and a wireless receiver to preferably electricallyinitiate pyrotechnic cutters rigged on traditional reefing lines withinthe canopy.

It is an object of the method for parachute reefing control of thepresent invention to provide a control processor which receives sensoryinput from load, altitude, mission time, pressure sensors and otherparameters to determine the best time to operate the reefing releasemechanism without requiring any physical connection for the controlbetween the payload and the parachute.

It is an object of the method for parachute reefing control of thepresent invention to provide a system which increases mission profileflexibility by building in known mission profiles that could becommanded by either a crew or a vehicle's flight computer.

It is an object of the method for parachute reefing control of thepresent invention to provide a system which would not need to be overbuilt to suit off nominal mission profile requirements.

It is an object of the method for parachute reefing control of thepresent invention to provide a system which could utilize small powersupplies installed adjacent to each electrically fired reefing cutter.

It is an object of the method for parachute reefing control of thepresent invention to provide a system which allows for controllingoperation of the reefing disengagement means to be mounted on thepayload and to be continuously and instantaneously responsive to sensedconditions ongoing.

It is an object of the method for parachute reefing control of thepresent invention to provide a system which allows for controllingoperation of the reefing disengagement means of multiple parachuteswhich are all connected to the same payload, commonly known as a clusterof parachutes, and, wherein each of these parachutes are disreefed in acoordinated manner to facilitate uniform canopy inflation among allparachutes in the cluster.

BRIEF DESCRIPTION OF THE DRAWING

While the invention is particularly pointed out and distinctly claimedin the concluding portions herein, a preferred embodiment is set forthin the following detailed description which may be best understood whenread in connection with the accompanying drawing, in which:

The FIGURE shows a schematic illustration of an embodiment of the methodand apparatus for parachute reefing control of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides an apparatus for parachute reefingcontrol which includes a vehicle or payload 10 such as a space capsulewhich includes a parachute 16 attached thereto. Both the payload 10 andthe parachute 16 are shown schematically in the FIGURE of the presentinvention. The parachute 16 includes a canopy 12 which is initiallycollapsed or packed and is reefed to restrict inflation thereof suchthat that movement toward the fully inflated state can be controlled. Aplurality of suspension lines 14 extend from the canopy 12 of parachute16 to the payload 10. In one common usage of the apparatus of thepresent invention is where the payload 10 is a space travel capsule isreturning from a mission wherein control of airborne descent thereof isprovided by the parachute 16 or a cluster of such parachutes.

In the present invention a canopy reefing device 18 is shownschematically in the FIGURE extending around the lower surface or edgeof the canopy 12 in order to selectively restrict inflation thereofuntil released. A reefing release mechanism 20 is also shown which mayinclude one or more individual reefing release devices. As shown in theFIGURE, the first reefing release device 54 and the back up firstreefing release device 57 are shown surrounding a reefing line 56, ormore particularly, extending around the first reefing line 72, whichrestricts inflation of the canopy 12 until released.

Thus, when the first reefing release device 54 is activated it will cutthe first line 72 in order to at least partially release the canopy 12.The first reefing release device 54 can also be provided with a backupor redundant device to be operable to cut first reefing line 72. Thebackup first reefing release device 57 provides this redundancy toassure that disreefing occurs despite any possible failure associatedwith the first reefing release device 54. Such a back up system may alsorequire a backup reefing release means 78 and a backup wireless receiver76.

Normally multiple stages of reefing of the canopy are provided and, assuch, multiple reefing release devices are required to fully release thecanopy to the full inflation. Such additional reefing release devicescan be included such as second reefing release device 55. This device 55is shown in the FIGURE herein surrounding a second reefing line 74 tofacilitate cutting thereof for disreefing the second stage of canopyreefing. It should also be appreciated that the present invention can bepracticed with any number of different stages incorporated into thereefing release mechanism 20. Use of as many as five or more stages isfairly common in some applications. Such reefing is shown schematicallyin the FIGURE wherein one frangible line 56 will usually be installed onthe canopy skirt for each stage of reefing. In the FIGURE a firstreefing line 72 and a second reefing line 74 are shown, as an example oftwo stage reefing but many others could be included, often configuredwith various sized lengths to facilitate staging of the reefing.Multiple stages of reefing configuration would normally be achieved byproviding multiple independent reefing lines of successively increasinglengths for allowing the canopy to inflate in progressive stages to fullinflation.

One of the unique optional aspects of the present invention is in theuse of a plurality or array of sensing devices 22 which are mounted withrespect to the payload 10. The sensing devices 22 are for the purposesof continuously monitoring various conditions or parameters in anongoing basis and providing this information to a reefing controlprocessor 32 which normally is a digital device such as a computer. Thereefing control processor 32 is operable to monitor the initiallyprovided mission profile or reefing release schedule based upon theinput from the various sensors in the array 22. As shown in theschematic diagram of the present invention, the initial mission profile28 is set prior to deployment of the parachute. This initial missionprofile for release of the reefing mechanism can be modified by thecontrol logic in the reefing control processor 32 in the continuousongoing feedback basis based upon the information received from thevarious sensors in the array 22.

The sensor array 22 can include a mission time clock 60. It also caninclude an altitude sensor 62. A global positioning system device 64 canbe another sensor included on the sensing array 22. Sensing array 22 canfurther include a pressure sensing means which monitors the dynamicpressure being exerted instantaneously on the payload. Another possibleparameter to be sensed by array 22 is the load force of the canopy. Eachof these parameters as well as other parameters which could be includedand are still within the contemplation of the present invention will becontinuously monitored in order to provide updated and currentinformation to the reefing control processor 32 for the purpose ofallowing the control processor through predetermined algorithms tomodify the schedule or profile of actuation of the reefing releasemechanism 20. With this construction the release profile can be modifiedeven at the very last split second prior to initiation of operation ofthe reefing release mechanism 20.

It should be appreciated that the use of the array of sensors is animportant optional aspect of the present invention but is not requiredin order to practice the basic concept. The reefing control processorwill be initially programmed with one or more basic reefing releaseschedule. The processor can be preprogrammed with several choices ofschedules, each of which is usable for different specific applications.Choice of the schedule or the programming of a customized schedule isfacilitated because the reefing control processor is attached to thepayload and is not packed within the parachute pack. Thus, the programcan be chosen even after the parachute is completely packed.

The reefing control processor can contain only a simple timetable whichwill be set by an operator prior to use without requiring any input fromany sensors. Thus the concept of the present invention allows formultiple and repeated use of a common parachute system across variousmission profiles. It is very simple and easy to make modifications toany pre-defined disreefing schedule at the payload where the processoris located and at a time after the common parachute system has alreadybeen packed for use. Of course, the inclusion of the array of sensorswith the input directed to the processor does provide a system which isadaptable to vary the disreefing schedule responsive to contemporaneouschanges in flight conditions. The predesignated timetables fordisreefing would also provide the reefing control processor with backupdisreefing control timetables in those situations where the sensors failto properly monitor flight conditions or fail to communicate theirreading to the processor.

The profile or schedule determined by the reefing control processor 32will be operative to generate one or more release signals such as firstrelease signal 34 and/or second release signal 36. At least one suchrelease signal will be required in all operations and, in thisembodiment, the first release signal 34 will then be communicated to theprimary wireless transmitter 38. This primary wireless transmitter 38will then generate a primary wireless signal. It is important toappreciate that the reefing control processor 32 as well as the primarywireless transmitter 38 and any other wireless transmitter utilized withthe apparatus of the present invention is attached with respect to thepayload. In this example the primary wireless transmitter 38 willgenerate this primary wireless signal 42 which is adapted to be receivedby a primary wireless receiver 46 which is mounted with respect to theparachute. Preferably the primary wireless receiver 46 will bepositioned immediately adjacent to the first stage reefing device 50which in this case is shown as an electrically activated pyrotechnicallyfired cutter. As shown in the FIGURE of the present invention the firststage reefing means and the backup first stage reefing means are bothshown in surrounding engagement to the first stage reefing line 72surrounding the canopy and shown schematically in the FIGURE. Each ispositioned immediately adjacent to a reefing release device. The firstreefing release device 54 is positioned immediately adjacent to thefirst stage reefing means 50 and is operable for release thereof.Preferably the first reefing release device 54 will achieve partial orfull disengagement of the canopy reefing device 18 but surely willachieve at least full releasing of the first stage reefing 50.

Similarly the second reefing release device 55 is shown immediatelyadjacent to the second stage reefing means 52. The second reefingrelease device 55 is operative responsive to receiving a secondarywireless signal 44 transmitted by a secondary wireless transmitter 40attached to the payload 10 in order to initiate operation of the secondreefing release device 55.

It is an important consideration of the present invention to realizethat the primary wireless transmitter 38 and the secondary wirelesstransmitter 40 will generate a primary wireless signal 42 and asecondary wireless signal 44 such as to be sensed by the primarywireless receiver 46 and, respectively, the secondary wireless receiver48 and initiate operation, respectively, of the first reefing releasedevice 54 and the second reefing release device 55. It is also importantto realize that the second reefing release device 55 can be constructedto release a second stage of reefing of the canopy. A backup releasemechanism can also be provided for any or all of the stages to beassured that the main reefing release device for that stage worksproperly. It is also possible that more than two stages of disreefingmay be required.

In utilizing the apparatus of the present invention, it is important tonote that the only means of connection between the canopy 12 and thepayload 10 is through the suspension lines 14. These suspension linesextend toward the payload and are attached to the payload at anattachment point 24 as shown schematically in the FIGURE. Commonly theactual attachment between the suspension lines and the payload isthrough another physical means such as a riser or bridle. There is noneed for any electrical lines or other hard wire communication betweenthe payload 10 and the canopy 12 because the signal for initiation ofoperation of the reefing release mechanism 20 is provided by wirelesstransmitters and receivers as well as a continuously automaticallyadjustable reefing control processor 32. The processor 32 shouldpreferably include its own separate processor power supply 26.

Two of the important sensors in the array of sensors 22 include the loadforce sensor 66 and the dynamic pressure sensor 68. Each of thesesensors monitor ongoing conditions which are very important in order todetermine the proper time for disengagement of the canopy reefing. Bypositioning the primary wireless receiver 46 and, if needed, thesecondary wireless receiver 48 in a position mounted on a canopy whereasthe transmitters 38 and 40 are mounted on the payload, a physicaldisengagement between the payload and the electrically controlledoperating means for disreefing in the canopy is provided. This isimportant since any such additional interconnections can often lead toimproper loads or entanglements or other problems which can be ofcritical importance in the midst of a rapid airborne descent of apayload and parachute apparatus.

A parachute deployment inhibiting device 70 can also be includedoperatively positioned between the reefing control processor and thewireless transmitters 38 and 40 in order to prevent deployment and/ordisreefing of the parachute unless the flight conditions are deemedacceptable as determined by the parameters being monitored by the arrayof sensing means which must be within predetermined tolerancelimitations. It is also noted that in the preferred configuration, theconfiguration of the reefing mechanism includes at least one restrictingline 56 which preferably can be cut by at least one electrically firedcutter 58. However, other means of restricting the canopy are providedand other means of releasing the reefing mechanism can also becontemplated and still be within the metes and bounds of the presentinvention.

It is important to consider that the present invention provides a meansfor mounting a plurality of sensors and a reefing disengagement profilecontroller mounted to the payload rather than to the parachute. Theparachutes are normally initially packed and, as such, access tocontrolling therewithin are severely restricted after packing. With theuse of the apparatus of the present invention the sensors are mounted tothe payload and the reefing control processor is also mounted on thepayload and wirelessly transmits information regarding reefing releaseto the canopy. As such, those controls are external to the parachutewhen packed and are available for setting of the mission profile inputor modifying of the algorithms in the reefing control processor 32 asneeded even after the parachute canopy and suspension lines arecompletely packed. This added flexibility greatly enhances operationalcontrol of the canopy deployment.

The apparatus of the present invention also allows parachute reefing tobe sequenced at optimal times in order to achieve a degree of trajectorycontrol and in this manner further enhance the possibility of preciselandings. Also, in the very unusual emergency circumstances, it may beneeded to have a very short reefing delay. The system of the presentinvention allows for prompt inflation when the system is deployed at alow altitude or at low air speed while also allowing the system to beadaptable to obtain extended reefing delay and prolonged inflation whendeployed at a high altitude or at high air speeds. Thus the array ofsensors for monitoring continuously variable parameters allows thepayload and parachute airborne descent control apparatus to be utilizedin a much wider spread of possible operating conditions than has beenavailable heretofore.

The present invention is particularly usable with payloads such as spacecapsules which often make use of a plurality or cluster of parachuteswhich are all simultaneously attached with respect to the same payload,namely, the capsule. Substantial uneven load distributions in themultiple parachutes can result with the current commonly used reefingcutters that are mechanically activated and which have pyrotechnic fusesfor setting time delay. The concept of the present invention is veryuseful for such applications because it can broadcast the disreefingsignal to all canopies in a cluster in a coordinated manner to maintainbalanced inflation of the respect canopies. The concept of the presentinvention is particularly useful for applications involving the use ofclusters of parachutes because a single processor can be used to fullycontrol the operation of sets of wireless transmitters and receiversassociated with each individual parachute in the cluster.

Optimization of the setting of the pre-designated time delay is animportant improvement made possible by the apparatus of the presentinvention. Pyrotechnic reefing cutters commonly used at this time aremechanically-actuated and, as such, provide only a limited selection ofdelay times and accuracies. Currently used electrically-actuated reefingcutters may have unlimited delay selection capabilities, but areconstrained by the bulk and mass of the wiring that is required. Theseproblems are overcome by the improved reefing control system of thepresent invention since an essentially unlimited variation in thepre-set reefing schedule timing is made possible. The only constraintson the operation of the improved design present herein is the basicaccuracy of the processor and the response characteristics of thewireless transmitting and receiving hardware.

While particular embodiments of this invention have been shown in thedrawing and described above, it will be apparent that many changes maybe made in the form, arrangement, and positioning of the variouselements of the combination. In consideration thereof, it should beunderstood that preferred embodiments of this invention disclosed hereinare intended to be illustrative only and not intended to limit the scopeof the invention.

1. A method for parachute reefing control for use with a payloadattached solely through suspension lines to a parachute having a canopywith a canopy reefing device and a reefing release mechanism forcontrolling canopy inflation and airborne descent after deploymentthereof, said method comprising: A. providing a reefing controlprocessor mounted on the payload which is preprogrammed with a releaseschedule for controlling release of the reefing of the parachute canopy;B. transmitting of at least one wireless release signal from the payloadto the reefing release mechanism mounted adjacent the reefing device atthe parachute canopy in accordance with the release schedule; C.receiving of the wireless release signal at a position adjacent thecanopy; and D. actuating a reefing release mechanism positioned adjacentto the canopy to allow at least partial inflation of the parachutecanopy to facilitate controlled descent thereof with the payloadattached thereto.
 2. A method for parachute reefing control as definedin claim 1 further comprising: A. monitoring a plurality of parameterswith sensors mounted with respect to the payload and communicating themonitored parameter information to the reefing control processor; and B.modifying of the preprogrammed reefing release schedule by operation ofthe reefing control processor responsive to the monitored parameterinformation received from the sensors.
 3. A method for parachute reefingcontrol as defined in claim 1 wherein said transmitting of at least onewireless release signal comprises transmitting a plurality of separatelyidentifiable release signals sequentially for actuating release of thereefed canopy in multiple stages from initially allowing only partialinflation thereof to full inflation thereof finally.
 4. A method forparachute reefing control as defined in claim 1 wherein said monitoringincludes monitoring the mission elapsed time.
 5. A method for parachutereefing control as defined in claim 2 wherein said monitoring includesmonitoring of the altitude of the payload from ground level therebelow.6. A method for parachute reefing control as defined in claim 2 whereinsaid monitoring includes operating of a global positioning system deviceto instantaneously determine the position of the payload.
 7. A methodfor parachute reefing control as defined in claim 2 wherein saidmonitoring includes monitoring the dynamic pressure being exertedinstantaneously on the payload.
 8. A method for parachute reefingcontrol as defined in claim 2 wherein said monitoring includesinstantaneously sensing the load force on the canopy.
 9. A method forparachute reefing control as defined in claim 2 further comprisingevaluating the monitored parameters instantaneously and selectivelypreventing initial deployment of the parachute and/or activation of aparachute reefing release mechanism responsive to determining that anyone of the sensed parameters are currently at a value which is outsideof predetermined or disreefing tolerance limiting values.
 10. A methodfor parachute reefing control for use with a payload attached solelythrough suspension lines to a plurality of individual parachutes, eachhaving an associated canopy with an associated canopy reefing device andan associated reefing release mechanism for controlling canopy inflationand airborne descent after deployment thereof, said method comprising:A. providing a reefing control processor mounted on the payload which ispreprogrammed with a release schedule for controlling release of thereefing of each of the parachute canopies; B. transmitting of at leastone wireless release signal from the payload to each reefing releasemechanism mounted adjacent to each reefing device at the associatedparachute canopy in accordance with the release schedule; C. receivingof the associated wireless release signal at a position adjacent eachassociated canopy; and D. actuating a reefing release mechanismpositioned adjacent to each canopy to allow at least partial inflationof the associated parachute canopy to facilitate controlled descentthereof with the payload attached thereto and coordination of theinflation of each of individual parachute canopies.